The present invention generally relates to the field of medical devices and procedures. More specifically, the invention relates to devices and methods for the re-attachment of soft tissue to bone.
Re-attachment of soft tissue to bone is often required in surgery. During athletic endeavors, work, falls, or repetitive use and aging, a ligament or tendon may be pathologically avulsed or torn from its normal insertion site. Soft tissue to bone re-attachment is then needed to return normal or near normal function to the limb or joint. Such re-attachment may be necessary anywhere within the body, including, by way of example but not by way of limitation, in the wrist, ankle, knee, or shoulder. Re-attachment is considered important for several reasons. First, it helps ensure proper healing. When a ligament has been torn away from its normal position of attachment to bone it may become bathed in synovial fluid, which is a poor healing environment. Second, even if the ligament does heal, it may heal in a stretched out or elongated position, possibly leading to residual joint laxity or dysfunction. Surgical repair may thereby become necessary to return proper structure and function to the joint. The present invention relates to the fixation of soft tissue to bone at its proper location and is suitable for use in many common surgical procedures including, by way of example but not limitation, rotator cuff repair, bankart repair, ligament avulsions from bone (knee, ankle, shoulder, wrist) and many others known to those of skill in the art. While the invention is suitable for use in open surgery, it is particularly useful for arthroscopic surgery.
The present invention is more fully described below. Many publications are cited herein and the entire disclosure of each such cited reference is hereby incorporated by reference in its entirety, and should be considered a part of this disclosure as if set forth in its entirety at the point of reference.
Several approaches for attaching soft tissue to bone exist in the art. Each suffers disadvantages.
One approach requires transossous suture tunnels. The use of such tunnels is described more fully in Shoulder Reconstruction by Charles S. Neer II (W. B. Saunders Co. 1990). Although appropriate for some cases, the use of bone tunnels can be difficult and generally requires large open incisions.
Another approach, which is especially useful in closed, arthroscopic or endoscopic settings, involves the use of suture anchors that allow quick fixation without the need for extensive exposure. A common problem among many such anchor systems is that they require knot tying of the attached sutures after the suture anchors are inserted into the bone and the sutures placed through the soft tissue.
One example of a suture anchor assembly is set forth in U.S. Pat. No. 5,441,502, which describes an anchor assembly having a pre-threaded suture positioned at the posterior of the anchor. After the suture anchor is properly deployed in the bone, the associated suture extends upwardly through the soft tissue. The free ends of the sutures are then tied to secure the soft tissue to the bone.
An important limitation of this prior art is the requirement for knot tying. Knot tying itself is time consuming and technically demanding, especially in an arthroscopic environment, where surgery is done in small spaces through small incisions. In addition, knot slippage or suture breakage during knot tying could lead to unsecured attachment of the soft tissue to bone, potentially adversely affecting the healing process.
Some non-suture anchor systems have been described, such as in U.S. Pat. Nos. 5,840,078, 5,013,316, and 4,532,926. However, fixation with these devices may not be as secure as that achieved with sutures. In addition, non-suture anchors offer fewer points of fixation, typically providing only one point of soft tissue to device fixation per device, and one point of device to bone fixation per device.
Staple-like devices have been used surgically to eliminate the need for suturing outside of the soft-tissue to bone context. U.S. Pat. Nos. 4,994,073 and 5,089,009 describe surgical skin fasteners that eliminate the need for suturing when joining adjacent portions of soft tissue. The fastener comprises a backspan and two prongs depending therefrom. The skin fasteners are mostly useful for joining two edges of body tissue together or for joining layers of tissue both laterally or laminarly as required in skin grafting. Other surgical tacks made of bioabsorbable material such as the bankart tack (Bionix) and the Suretek (Acufex) leave hard polylactic or polyglycolic acid portions of the tack exposed. These exposed hard polymers pose potential injury to the articular cartilage or if broken off, may result in loose bodies, which may cause further joint deterioration or mechanical symptoms.
Staple-like devices have also been used for attaching bone to bone. U.S. Pat. No. 4,994,063 describes a bone staple with two feet and a central web portion made of rigid material. Portions of bone on opposite sides of a fracture are compressed toward each other by inserting the two feet of the staple into each bone portion and crimping the central web portion of the staple.
Staple-like devices having large rigid bodies have also been used to attach artificial soft tissue to bone. U.S. Pat. No. 4,793,335 describes a bone implant composed of a deformable metal plate and a pair of anchor pins attached to and extending from the metal plate. The staple described therein is used to hold a tendon or ligament over a relatively large area. These staples are not suitable for intra-articular usage because they tend to loosen in time with cyclical loading of the tissues and may become a loose object within the joint, causing further injury.
The invention relates to devices and methods for re-attaching soft tissue to bone. The invention is based in part on the discovery of an assembly comprising at least one suture joining multiple cannulated or non-cannulated anchors. This invention also relates to cannulated instruments to apply the suture-anchor assembly. Although the invention includes within its scope assemblies comprising multiple sutures or multiple anchors, in one embodiment a single suture is joined by two cannulated anchors. In this embodiment, the two cannulated anchors joined by suture can be easily and precisely inserted over guide wires at an optimal point of fixation through one larger arthroscopic cannula, thereby providing a knotless mechanism for attachment of soft tissue to bone having two points of fixation for a single suture. The invention thereby avoids the problems of the prior art associated with knot tying while at the same time providing improved structural and performance characteristics such as increased number of points of fixation per suture and facilitated arthroscopic insertion and placement. The invention also minimizes the risk of a portion of the device breaking off and becoming loose within the joint.
As used herein, the word xe2x80x9cre-attach,xe2x80x9d and all forms thereof such as xe2x80x9cre-attached,xe2x80x9d xe2x80x9cre-attachment,xe2x80x9d and xe2x80x9cre-attaching,xe2x80x9d is intended to include not only its ordinary meaning but also the concept of xe2x80x9cattach.xe2x80x9d Therefore, the term will be understood to properly describe any situation in which components are being attached, regardless of whether they had been attached previously.
In accordance with one aspect of the present invention, a system for attaching soft tissue to bone is provided. The system is composed of one integrated assembly. The integrated assembly is composed of at least two anchors, each having a region for insertion into the bone and a region for suture connection and at least one knotless suture attached to the suture connection region of each anchor. In one embodiment, at least one or both of the anchors is cannulated.
In accordance with another aspect of the present invention, the assembly includes the suture being attached eccentrically to the insertion region of at least one of the anchors.
In accordance with another aspect of the present invention, the system further includes a gun for firing the assembly.
In accordance with another aspect of the present invention, the system further includes a grasper tool having at least one cannulated barrel.
In accordance with still another aspect of the present invention, the system includes an initial anchor impactor tool and a final impactor tool, each of said tools adapted to apply force to at least one of the anchors for insertion into soft tissue and/or bone.
In accordance with still another aspect of the present invention, the system for attaching soft tissue to bone includes an assembly that is composed of at least two anchors, each having a region for insertion into the bone and a region for suture connection. The region for suture connection on at least one anchor includes a rotatable collar that can rotate relative to that anchor so that the suture is prevented from rotational movement with the anchor as the anchor is rotated, such as during insertion into the bone or other areas.
In accordance with still another aspect of the present invention, a method for attaching soft tissue to bone is provided. The method includes inserting at least two guidewires through the soft tissue and into the bone, inserting at least two anchors along the guidewires with the anchors being connected by a suture and thereafter inserting the anchors into the bone.
In accordance with another aspect of the present invention, a method for attaching soft tissue to bone is provided that comprises providing an assembly for attaching soft tissue to bone wherein the assembly is composed of at least two anchors, each anchor having an insertion region for insertion into the bone and a suture region for suture connection and a suture attached to the suture connection region of each anchor into the bone while the suture is attached to the suture connection region of each anchor.